Voltage Sensing Phase Failure Relays

Micro Controller based Voltage Protection Relay we supply has an in built feature of Single Phase Protection. If any of the phase is fail, within predefine time relay gets trip & at the same time displays SPP in its seven segment LED display. It can also synchronize with ACB in LT connection to get very accurate protection in case of Single Phasing / Phase Reversal from feeder (Electricity Board) supply & helps to prevent the same fault transfer to the whole system.

Voltage Protection Relays

We supply Micro Controller based Voltage Protection Relay for 3 Phase 3 Wire as well as 3 Phase 4 Wire Systems. It monitors phase to phase voltage & displays the same in Seven segment four digit LED display. The mounting of a relay is so easy that it can be directly replace with conventional Analogue Volt-meter. It is having auto scrolling facility, so no need to put selector switch for viewing different phases.

This relay is very useful for protection at incoming supply of PCC (Power Control Center), MCC (Motor Control Centre), on power line which feeds supply to sophisticated equipments / devices like PLC, Drives and DCS.

It can also synchronise with ACB in LT connection to get very accurate protection in case of Single Phasing / Phase Reversal from feeder (Electricity Board) supply & helps to prevent the same fault transfer to the whole system.

Phase Sequence Failure Relay

Phase sequence failure or phase reversal in a three phase induction motor can be dangerous when the opposite direction not allow in certain applications like Non reversing gear box, Screw Compressors, Certain Specialized Pumps, Blower fan etc. In certain cases it hazards to operating personnel. Phase reversal in a motor feeder produces a negative sequence of nearly 100% and is well detected by a relay with negative sequence / Phase Reverse protection. Considering the above details, it can be easily concluded that a motor protection relay will provide an effective protection to the motor only when it is equipped to measure the negative sequence component level in the motor feeder. Our Micro Controller based Motor Protection Device provides such protection. The same feature can be made disable when relay is used for Crane, Hoist or any other application when Motor rotates in Forward & Reverse both direction.

Digital Voltage Relay

We supply Micro Controller based Voltage Protection Relay with LED type Digital Display. The Digital Display continuously displays line voltage between two phases. In case any abnormal situation takes place, the relay trips & the same time displays the reason of trip through seven segment LED display.

Phase Failure Relays

During single phasing condition remaining two phases draw more currents (2-4 times of normal full load current). This is sensed as overload condition by Bi-Metallic Relay & it trips as per time proportionate to percentage of overload current. These currents are maximum at 100% loading hence relay has minimum tripping time delay, which is around 8-12 seconds.But if single phasing occur during partial loading condition, Bi-Metallic Relay will have longer tripping time.

”If motor loading is below 57% Bi-Metallic Relay will not trip if single phasing occurs.”

Single Phasing Protection of Micro Controller Relay is independent of loading conditions. This is most important because motor needs to be protected against single phasing faults at all loading conditions.

The operation of Micro Controller based motor protection relays are not hampered by frequency of operations or operating temperature. As against this, the working of thermal relays changes with these conditions.

In Micro Controller based Motor Protection tripping time is very fast & accurate, but in case of thermal overload relay it is slow & due to that wide band accuracy is very poor.